Are bees gardening?

An interesting paper in Science* suggests they are – well buff-tailed bumblebees anyway.

This superb photo of a buff-tailed bumblebee Bombus terrestris on crown vetch flowers was taken by our Senior Ecologist, Kevin McGee ©.

As if we need more evidence of climate change, researchers in Switzerland have found that buff-tailed bumblebees Bombus terrestris (Linnaeus, 1758), a species common in Britain, finding fewer flowers than they need after emerging from hibernation earlier than they used to as springs get warmer, seem to be manipulating plants to flower earlier. The bees are hungry and appear to have a trick that provides them with the pollen they eat much sooner than usual.Keeping their habits in tune with pollen production is known as phenological synchrony.

So how can this bee? (sorry). Well, the researchers noted the bees were damaging the plants with their mouthparts, making small holes in the leaves. The damaged plants flowered two to four weeks early, providing pollen for the bees which would otherwise starve. The researchers tried to mimic this damage themselves on plants but could not induce precocious flowering. The conclusion is that there is more to it than just making holes, perhaps chemicals in the bees’ saliva are the cause or some other distinct mechanism, but that is still to be determined.

Betts Ecology put much effort into protecting and enhancing ecological communities on our sites, taking an ecosystem approach that recognises the intricate relationship of all the species associated with a habitat. We work hard to avoid over-intensive mowing and cutting flowering swards at the wrong time, such as before seeds have ripened and fallen. We receive a lot of stick from people about this but we try to explain that, if we are to maintain and enhance biodiversity, we must learn to eschew scalped species-poor grass, thrashed hedges, and “lollipop” trees.

© Betts Ecology

* Chittka, L. (2020) The secret lives of bees as horticulturists? Science, 368 (649322), pp 824–825.